Selection of gentamicin-resistant variants of Pseudomonas aeruginosa in the rat cornea.

Pseudomonas aeruginosa often persists in ocular infections despite intensive antimicrobial therapy. In this study, gentamicin-resistant small colony variants (SCV) were selected in vitro from three gentamicin-susceptible Pseudomonas isolates by incubation with antibiotic. In the rat cornea, SCV were selected from two of these strains by administration of gentamicin either topically or intravenously. The selection of resistant variants may be a contributing factor in the persistence and reactivation frequently associated with ocular Pseudomonas infections.